A computer implemented visual image can be represented by a digital signal. Such a digital signal comprises a pixel map of pixel data representing a set of pixels that are displayed by a computer on a computer screen. However, a large volume of such pixel data is required to accurately represent a visual image using every pixel on the computer screen. Further, in the case of a moving visual images (video image) rather than a single, fixed visual image (still image), an even larger amount of pixel data is necessary to represent every frame in the video image. The large volume of pixel data required to represent an image may exceed or greatly inhibit the capacity of a storage device. Additionally, where a visual image is to be displayed on a remote device, especially in the case of a video image, the large amount of digital data often cannot be efficiently transmitted to the remote device within the limitations of existing media.
Various methods of data compression, often called image compression, have been employed to minimize the above problems. However, there is typically a limit to the extent that pixel data can be compressed without losing accuracy of the pixel data, and thus quality of the visual image, upon decompression. In general, with such methods, image quality deteriorates as data compression increases. As a result, the quality of visual images is limited to a significant extent in a wide variety of media and configurations. Thus, a more efficient means of image compression is desired which does not significantly reduce the quality of visual images.